Stabilization of rubbery copolymers with stannous phenylcatecholates



Patented July 4, 1950 UNITED STATES PATENT OFFICE STABILIZATION OFRUBBERY CO'POLYMERS WITH STAN N OUS PHENYLCATECHOLATES "Harry E. Albert,Akron, Ohio, assignor to The Firestone Tire & Rubber Company, Akron,Ohio, a corporation of Ohio No Drawing. Griginal application January 10,

1948, Serial No. 1,674. Divided and this application November 2, 1949,Serial No. 125,151

6 Claims. (Cl. 260-45375) Stannous 4-phenyl-6-chlorocatecholate Stannousit-phenyl-G-tert-butylcatecholate Stannous 4(ch1orophenyl) catecholateStannous 4(bromophenyl) catecholate Stannous4-tert-butyl-6-phenylcatecholate Stannous4-tert-octyl-fi-phenylcatecholate Stannous 4-chloro-G-phenylcatecholateStannous 4-bromo-G-phenylcatecholate Stamuouse-phenyl-S-tert-amylcatecholate Stannous 4-phenyl-6-bromocatecholateStannous 4-phenyl-B-fiuorocatecholate Stannous 4-phenyl-6-normal-decylcatecholate Thus, orthoand paraphenylcatecholates with The followingillustrates one method of preparing the compounds:

EXAMPLE 5 StlZIIJlO'LLS p-phenylcotecholate Thirty-seven grams ofBA-dihydroxydirbhenyl (p-phenylcate'chol) was dissolved in 50 per centethyl alcohol, and'a solution of 45.2 grams of stannous chloridedihydrate in alcohol was added. Tothe resulting solution, a solution of16 grams of sodium hydroxide in 200 ml. of-50 per-cent alcohol-water wasadded slowly during stirring. The precipitate was filtered, and thenwashed successively with 100 ml. portions of 50 per cent ethyl alcohol,ethyl alcohol, and water. It was air-dried and found to weigh 51 grams.On heating, it decomposed before melting. Analysis: Calculated,Tin=40.0% Found,- Tin: 44.9%.

20 This stabilizer was tested against phenyl-betanaphthylamineby-zadding small amounts of each to latex resulting 'from thecopolym'erization of 1,3-butadiene and styrene in the proportions togive the copolymer known as GR-S. The latices were coagulated, dried andaged, The products were tested manually to determine whetherresinification or other deterioration had set in. The results of thetests are recorded in the r01 lowing table.

'Table I After Drying 20 After aging 4 After aging 1 day Hours at 0.days at C. at 0. Stabilizer Color Hand Test Color Hand Test I Color BandTest 1%hst1a1iinous p-phenylcate- Light cream No deterioration,Very'light No deterioration Lightbrown Slig'litly set up.

0 o a e. 2%hst1a11 nons p-phenylcatedo do Very light brown. do do Do.

0 o a e. 1% phenyI-veta-naphthyla- Brown do he... Brown do Brown.-Considerably set up. mine. a I 2% phenyl-beta-naphthylado do do .doDarkbro'w'm Do.

mine.

halogen in either ring and an alkyl group "com taining up to ten carbonatoms ineither ring are included as stabilizers of this invention. Thesestabilizers include stannous salts of ort hoand para-'phe'nylcatecholates substituted in either ring with any =alkyl groupcontaining up to twenty or more carbonsatoms, and thus include dodecyl,octadecyl, etc, in either ring.

The above data show that the testmaterial 5 discolors less than thecommercial stabilizer. 'It

50 per "cent of each stabilizer were dried and then oven-aged at 90C.,.the results were:

Table II Oven-Aging After Drying 20 hours at 75 0. Stabilizer 2 Days 4Days Color Condition Condition Condition fltlarilous p-phenylcatecho-Light gray-green N o deterioratiom- Slightly set up Slightly set up.

a Phony]-beta-naphthylamine Brown do considerably set up. Cured.

The samples of Table I were coagulated with purified aluminum sulfate,and those of Table II The latex was coagulated. The coagula were driedand aged 4 days at 90 C. The following were coagulated with commercialaluminum table records the results: sulfate. Both tests show the teststabilizer dis- Tabzev colors less than the commercial stabilizer andalso gives improved protection to the copolymer. Color and Condition Thecopolymer coagula containing 2 per cent H Color after After Aging of therespective stabilizers were compounded Stablhze Drying according to thefollowing formula: Color Condition Parts by Weight t h 1 m h 1 t Wh't To a 5811110118 BVCB. 0 i copolymer containing 2% stab 100-0 phenyl-bgt nphthylamgn ei Light brown B wn i o. Coal tar plast1c1zer 3.0 Pme F Thus,the stabilizers of this invention are ef- Steanc F fective in rubberycopolymers of a conjugated Zinc oxlde diene monomer and a vinyl monomer.The con- Accelera'tor jugated-diene monomers include, for example,Channel black 1,3-butadiene, isoprene, 2-cyanobutadiene-1,3, sulfur 3Ocyclopentadiene, piperylene, dimethylbutadiene- The stocks were curedfor 40, 60, 80 and 120 1,3, 2-methylbutadiene-1,3, etc. The vinylmonminutes at 280 F. Some of the cured stocks omers include, forexample, aromatic monomers were aged 4 days in an oven at 212 F. Thesuch as, for example, tyrene, alpha methylstyphysical properties of thestocks were then derene, nuclearly substituted styrenes,monochlorotermined. In Table III, for each property avstyrene,dichlorostyrene,vinylnaphthalene,vinylerage values for the four curesare presented. biphenyl, vinylcarbazole, etc.; and aliphatic Table IIImyM Elongation at a oduJus Tensile Strength Break Stabilizer Normal AgedNormal Aged Normal Aged stannous p-phenylcatecho- 455 1, 465 2,785 2,340 685 350 phenyl-beta-naphthylamine.. 580 1,605 2,885 2,570 585 300(Modulus and tensile strength are measured herein in pounds per squareinch.)

The stock containing the test material compares favorably with thatcontaining the'commercia stabilizer.

Stocks similarly compounded from copolymer containing 2 per cent of thediiierent stabilizers were cured and aged 10 hours in an air bomb atlowing tests show the results of such aging:

monomers such as, for example, acrylomtrile, methacrylonitrile,alpha-chloracrylonitrile, acrylamide, acrylic-acid alkyl esters in whichthe alkyl radical contains one to five carbon atoms, alkyl-acrylicketones in which the alkyl group a contains one to five carbon atoms,etc. 260 13. under pounds air pressure. The fol- 55 The stabilizer maybe used with other stabilizer. It may be used in amounts ranging fromTable IV 200% Modulus Tensile Strength ggy? at Stabilizer Normal AgedNormal Aged Normal Aged stannousp -phenylcatecholate- 455 1,330 7 2,7852,625 685 380 phenyl-beta-naphthylamine. .580 1,540 2,885 2,630 585 3350.1 to 10.0 per cent. The invention is defined in the claims.

What I claim is:

1. Rubbery copolymer of a conjugated-dime monomer and a vinyl monomerstabilized with a small amount of stannous p-phenylcatecholate.

2. Uncured rubbery copolymer of 1,3-butadiene and styrene stabilizedwith a. small amount of stannous p-phenylcatecholate. 1

3. Uncured. rubbery copolymer of LS-butadiene and acrylonitrilestabilized with a small amount of stannous p-phenylcatecholate.

4. Cured rubbery copolymer of LS-butadiene and styrene stabilized with asmall amount of stannous p-phenylcatecholate.

5. Cured rubbery copolymer of 1,3-butadiene and. acrylonitrilestabilized with a small amount of stannous p-phenylcatecholate.

6. The process of stabilizing a rubbery copolymer of a conjugated-dienemonomer and a, vinyl monomer which comprises mixing therewith stannousp-phenylcatecholate.

HARRY E. ALBERT.

No references cited.

1. RUBBERY COPOLYMER OF A CONJUGATED-DIENE MONOMER AND A VINYL MONOMERSTABILIZED WITH A SMALL AMOUNT OF STANNOUS P-PHENYLCATECHOLATE.